U.S. patent number 6,863,650 [Application Number 09/488,500] was granted by the patent office on 2005-03-08 for endoscopic instrument for performing endoscopic procedures or examinations.
This patent grant is currently assigned to Karl Storz GmbH & Co. KG. Invention is credited to Klaus M. Irion.
United States Patent |
6,863,650 |
Irion |
March 8, 2005 |
Endoscopic instrument for performing endoscopic procedures or
examinations
Abstract
An endoscopic instrument, comprises a shaft, a handle arranged
at a proximal end of said shaft, at least one working part arranged
at a distal end of said shaft, and at least one marking having a
fluorescing substance that can be excited to fluoresce by a light
source, said marking is provided at a distal end section of said
instrument. Said fluorescing substance is selected in such a way
that its exciting range lies in an excitation range of a
tumor-specific photosensitizer or in an excitation range of a
tissue autofluorescence.
Inventors: |
Irion; Klaus M. (Liptingen,
DE) |
Assignee: |
Karl Storz GmbH & Co. KG
(DE)
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Family
ID: |
7836795 |
Appl.
No.: |
09/488,500 |
Filed: |
January 20, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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PCTEP9804575 |
Jul 21, 1998 |
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Foreign Application Priority Data
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Jul 24, 1997 [DE] |
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197 31 894 |
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Current U.S.
Class: |
600/104;
600/117 |
Current CPC
Class: |
A61B
17/320016 (20130101); A61B 2090/3941 (20160201) |
Current International
Class: |
A61B
17/32 (20060101); A61B 19/00 (20060101); A61B
001/00 (); A61B 001/04 () |
Field of
Search: |
;600/101,104,117,139
;606/205-209 |
References Cited
[Referenced By]
U.S. Patent Documents
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4541438 |
September 1985 |
Parker et al. |
4918000 |
April 1990 |
Schubert |
6258576 |
July 2001 |
Richards-Kortum et al. |
6294331 |
September 2001 |
Ried et al. |
|
Primary Examiner: Yu; Justine R.
Assistant Examiner: Mathew; Fenn C.
Attorney, Agent or Firm: St. Onge Steward Johnston &
Reens LLC
Parent Case Text
CROSSREFERENCE OF PENDING APPLICATION
This application is a continuation of pending international
application PCT/EP 98/04575 filed on Jul. 21, 1998.
Claims
What is claimed is:
1. An endoscopic system comprising an endoscopic instrument and a
light source, said endoscopic instrument comprising: a shaft, a
handle arranged at a proximal end of said shaft, at least one
working part arranged at a distal end of said shaft, and at least
one fluorescent marking, having a fluorescing substance that can be
excited to fluoresce by a light source, said marking is provided at
a distal end section of said endoscopic instrument, wherein said
fluorescing substance is selected in such a way that its excitation
range lies in an excitation range of a tumor-specific
photosensitizer applied to tissue surrounding said endoscopic
instrument, said light source is selected in a way that it only
emits light of specific wavelength ranges matching excitation
ranges of both said fluorescent marking of said instrument and the
tissue surrounding said endoscopic instrument to which said tumor
specific photosensitizer has been applied, therefore said same
light source can excite both fluorescence phenomena.
2. The endoscopic system of claim 1, wherein said fluorescing
substance is selected to be excited in a range from 370 nm to 440
nm.
3. The endoscopic system of claim 1, wherein said marking is
configured as a marking element applied on said endoscopic
instrument.
4. The endoscopic system of claim 3, wherein said marking element
is applied removably.
5. The endoscopic system of claim 1, wherein said at least one
distal working element is equipped with said marking.
6. The endoscopic system of claim 5, wherein two working elements
are present and are configured as two mouth parts that are each
equipped with a marking.
7. The endoscopic system of claim 1, wherein a marking is
respectively provided both on said at least one working element and
in a distal end section of said shaft.
8. The endoscopic system of claim 1, wherein said shaft is
configured as a tubular shaft, and wherein said marking is
configured as a tubular bushing that can be slid onto said tubular
shaft.
9. The endoscopic system of claim 1, wherein said marking is
provided with a coating, made of a transparent material, that
covers said fluorescing substance.
10. The endoscopic system of claim 1, wherein said marking is
configured as a marking element applied on said endoscopic
instrument, said marking element can be inserted into a body on
which an endoscopic procedure is being performed, and said marking
element can be anchored there.
11. The endoscopic system of claim 1, wherein said fluorescing
substance is selected from the group consisting of fluorescein,
eosin, the porphyrins, cadmium sulfide, aminolevulinic acid,
aminolevulinic acid hydrochloride, Acridine Orange, tetracyclines,
auramine, rhodamine B, rhodamine G, auramine Carbol Fuchsin, and
Nile Blue sulfate.
12. The endoscopic system of claim 1, wherein multiple markings
with differently excitable fluorescing substances are provided.
13. The endoscopic system of claim 1, wherein multiple markings
containing different concentrations of said fluorescing substance
are present.
14. The endoscopic system of claim 1, wherein said marking is
configured as a marking element that can be inserted into a body on
which an endoscopic procedure is being performed, and can be
anchored there, and wherein said marking element has a fluorescing
substance corresponding to said of a further marking element
inserted into said body.
15. The endoscopic system of claim 1, further containing a
light-supplying apparatus and an endoscopic observation instrument
that is connected to a light source, selected in such a way that
said fluorescing substance can be excited to fluoresce by said
light source.
16. The endoscopic system of claim 15, wherein said observation
instrument is an endoscope.
17. The endoscopic system of claim 16, wherein said endoscope is
equipped with an endoscopic camera.
18. The endoscopic system of claim 17, wherein there is provided
downstream from said endoscopic camera an image processing system
that continuously detects said fluorescing markings in an
endoscopic image.
19. The endoscopic system of claim 1, wherein at least one
endoscopic manipulation instrument is provided, through which an
observation element can be introduced into a body, and at least one
marking with a fluorescing substance corresponding to the marking
of said endoscopic instrument is provided on an inner side of said
manipulation instrument.
20. The endoscopic system of claim 19, wherein said manipulation
instrument is a trokar and said observation element is an
endoscope.
21. The endoscopic system of claim 18, wherein said light source
emits pulsed light at least in a spectral excitation range of said
fluorescing substance, and a pulse frequency corresponds to a video
image frequency of said endoscopic camera.
22. The endoscopic system of claim 20, wherein said observation
instrument has, at a distal end thereof, a transparent element
having a fluorescing substance.
23. An endoscopic system comprising an endoscopic instrument and a
light source, said endoscopic instrument comprising: a shaft, a
handle arranged at a proximal end of said shaft, at least one
working part arranged at a distal end of said shaft, and at least
one fluorescent marking, having a fluorescing substance that can be
excited to fluoresce by a light source, said marking is provided at
a distal end section of said endoscopic instrument, wherein said
fluorescing substance is selected in such a way that its excitation
range lies in an excitation range of a tissue-autofluorescence of
tissue surrounding said endoscopic instrument, said light source is
selected in a way that it only emits light of specific wavelength
ranges matching excitation ranges of both said fluorescent marking
of said instrument and said tissue auto-fluorescence of the tissue
surrounding said endoscopic instrument, therefore said same light
source can excite both fluorescence phenomena.
24. The endoscopic system of claim 23, wherein said fluorescing
substance can be excited in a range from 400 nm to 500 nm.
25. The endoscopic system of claim 23, wherein said marking is
configured as a marking element applied on said endoscopic
instrument.
26. The endoscopic system of claim 25, wherein said marking element
is applied removably.
27. The endoscopic system of claims 23, wherein said at least one
distal working element is equipped with a marking.
28. The endoscopic system of claim 27, wherein two working elements
are present and are configured as two mouth parts that are each
equipped with a marking.
29. The endoscopic system of claim 23, wherein a marking is
respectively provided both on said at least one working element and
in a distal end section of said shaft.
30. The endoscopic system of claim 23, wherein said shaft is
configured as a tubular shaft, and wherein, said marking is
configured as a tubular bushing that can be slid onto said tubular
shaft.
31. The endoscopic system of claim 23, wherein said marking is
provided with a coating, made of a transparent material, that
covers said fluorescing substance.
32. The endoscopic system of claim 23, wherein said marking is
configured as a marking element applied on said endoscopic
instrument, said marking element can be inserted into a body on
which an endoscopic procedure is being performed, and said marking
element can be anchored there.
33. The endoscopic system of claim 23, wherein said fluorescing
substance is selected from the group consisting of fluorescein,
eosin, the porphyrins, cadmium sulfide, aminolevulinic acid,
aminolevulinic acid hydrochloride, Acridine Orange, tetracyclines,
auramine, rhodamine B, rhodamine G, auramine Carbol Fuchsin, and
Nile Blue sulfate.
34. The endoscopic system of claim 23, wherein multiple markings
with differently excitable fluorescing substances are provided.
35. The endoscopic system of claim 23, wherein multiple markings
containing different concentrations of said fluorescing substance
are present.
36. The endoscopic system of claim 23, wherein said marking is
configured as a marking element that can be inserted into a body on
which an endoscopic procedure is being performed, and can be
anchored there, and wherein said marking element has a fluorescing
substance corresponding to said of a further marking element
inserted into said body.
37. The endoscopic system of claim 23, further containing a
light-supplying apparatus and an endoscopic observation instrument
that is connected to a light source, selected in such a way that
said fluorescing substance can be excited to fluoresce by said
light source.
38. The endoscopic system of claim 37, wherein said observation
instrument is an endoscope.
39. The endoscopic system of claim 38, wherein said endoscope is
equipped with an endoscopic camera.
40. The endoscopic system of claim 39, wherein there is provided
downstream from said endoscopic camera an image processing system
that continuously detects said fluorescing markings in an
endoscopic image.
41. The endoscopic system of claim 23, wherein at least one
endoscopic manipulation instrument is provided, through which an
observation element can be introduced into a body, and at least one
marking with a fluorescing substance corresponding to the marking
of said endoscopic instrument is provided on an inner side of said
manipulation instrument.
42. The endoscopic system of claim 41, wherein said manipulation
instrument is a trokar and said observation element is an
endoscope.
43. The endoscopic system of claim 40, wherein said light source
emits pulsed light at least in a spectral excitation range of the
fluorescing substance, and a pulse frequency corresponds to a video
image frequency of said endoscopic camera.
44. The endoscopic system of claim 42, wherein said observation
instrument has, at a distal end thereof, a transparent element
having a fluorescing substance.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an endoscopic instrument for
performing endoscopic procedures or examinations, having a shaft, a
handle arranged at the proximal end of the shaft, and at least one
working element arranged at the distal end of the shaft, in
particular mouth parts.
The invention further relates to an endoscopic instrument suite
that contains such an endoscopic instrument and also a
light-supplying apparatus and an endoscopic observation instrument,
in particular an endoscope, that is connected to a light
source.
Endoscopic instruments and endoscopic instrument suites of this
kind are commonly known, and are used in the increasingly
widespread practice of minimally invasive surgery.
The methods of photodynamic diagnosis (PDD) and photodynamic
therapy (PDT) are increasingly being used in endoscopy to detect
and treat tissue changes. The offprint from Endo World, URO No.
17/1-D, 1997, "Photodynamic diagnosis (PDD) for early detection of
bladder carcinoma" [Photodynamische Diagnose (PDD) zur
Fruherkennung des Harnblasenkarzinoms] of Karl Storz GmbH &
Co., Tuttlingen, Germany, discloses a system used, in conjunction
with a photosensitizer that accumulates in tumor-specific fashion
and exhibits fluorescence under specific excitation light, to
detect tumors or malignant tissue changes. Aminolevulinic acid
(ALA), for example, is used successfully as a precursor of a
photosensitizer of this kind.
It is known from U.S. Pat. No. 5,408,996 to detect malignant tissue
endoscopically by causing fluorescence of a marking substance
conveyed to the tissue.
Tissue changes can also be detected on the basis of
"autofluorescence" triggered by natural fluorescent substances
occurring superficially in external tissue layers.
In all these methods, light (called "excitation light") in a
specific wavelength range is coupled into the tissue region
containing the fluorescent substance, and that fluorescent
substance is thereby excited to fluoresce. The fluorescence
wavelength range is always of longer wavelength than the excitation
range. When ALA is used as the precursor for the tumor-specific
photosensitizer photoporphyrin, excitation is performed in the blue
(380 to 340 nm), and fluorescence occurs in the red (635 nm). The
manner in which fluorescent excitation, as opposed to normal or
so-called "white" light, can make a tumor visible in clearly
defined fashion is strikingly evident from page 5 of the
aforementioned "Endo World" brochure. Even tiny satellite tumors of
a fluorescing papillary tumor can be detected in a manner clearly
differentiated from the principal tumor, and can be appropriately
treated or removed in a surgical endoscopic procedure.
In autofluorescence examinations, the excitation can also occur in
the blue and the fluorescence appears principally in the green and
red spectral region. Excitation can also be performed in the UV
range.
Since the fluorescence intensity is much lower than the excitation
intensity, the spectral region of the excitation light is almost
completely blocked out in the receiving observing system by
filters, to allow detection of the fluorescent emission. Only the
fluorescing areas are clearly visible.
This has the disadvantageous consequence that when instruments are
introduced into the region illuminated and imaged by the endoscope,
these instruments are difficult or in fact impossible to detect
when the illumination system is operating in fluorescence mode. In
other words, a surgeon watching the surgical procedure via an
endoscope, cannot see the instrument in the fluorescence
illumination mode. It has therefore hitherto been necessary to
switch over continually from fluorescence mode to white-light mode,
and vice versa, in order to bring an instrument accurately to the
tissue area that is to be examined or treated. This is cumbersome,
extremely laborious and irritating to the surgeon, and most of all
hazardous or critical in terms of the procedure.
These instruments can be of many different kinds. They can be
instruments used in examinations (diagnosis) or also in surgical
procedures (therapy).
It is fundamentally known from DE 39 33 199 C2 to equip the distal
end piece of a flexible endoscope with a marking which makes it
possible to view the end piece in the context of X-ray
examinations.
It is the object of the present invention to create an endoscopic
instrument that is clearly detectable even in fluorescence mode,
and to create an endoscopic instrument with which endoscopic
surgical procedures or examinations can be performed under
fluorescence conditions.
SUMMARY OF THE INVENTION
According to the present invention, the endoscopic instrument is
provided with at least one marking having a fluorescing substance
that can be excited to fluoresce by a light source, said marking is
provided in the distal end section at the instrument.
In one embodiment, the fluorescing substance is selected in such a
way that its excitation range lies in the excitation range of a
tissue autofluorescence.
It is preferred in this context if the fluorescing substance can be
excited in a range from 400 nm to 500 nm.
The considerable advantage of this feature is that because, as
mentioned earlier, tissue autofluorescence is extremely weak, the
excitation frequency used is not a different one that interferes
with that autofluorescence but instead precisely the same
excitation range, so that then the corresponding fluorescence is
obtained in the same way as the autofluorescence.
In another embodiment, the fluorescing substance is selected so
that its excitation range lies in the excitation range of a
tumor-specific photosensitizer.
In the context of this embodiment, it is particularly preferred to
perform excitation in an excitation range from 370 nm to 440
nm.
This feature has the general advantage that excitation is performed
only with a very specific excitation range, and fluorescence is
produced both in the tumor and also on the marked instrument.
Mutual interfering influences upon excitation of the tumor-specific
photosensitizer on the one hand and of the fluorescing substance of
the marking on the other hand are then no longer possible, and are
thus inherently ruled out by the system. The aforementioned
wavelength range in the range from 370 nm to 440 nm is an
excitation range for exciting the photosensitizer induced by ALA
that is usable for marking tumors.
A "light source" for the purposes of the present invention is
understood to be a radiation source that radiates light in the UV,
visible, and/or IR range. Unlike X-ray light, light in this
wavelength range does not adversely affect or even damage the
tissue of the body being examined or treated, or the observer, so
that even extended operations, or numerous surgical procedures
performed by the surgeon in fluorescence mode, can be carried out
without radiation damage.
Because of the fluorescent marking, it is now possible to clearly
recognize an instrument in fluorescence mode and moreover to
determine unequivocally its position relative to the tissue that is
to be examined or removed. As a result it is easily possible, under
fluorescent diagnostic light conditions, to bring, for example, a
biopsy forceps or another instrument, for example a laser fiber, to
the fluorescing tumor area under endoscopic observation and, for
example, to take a tissue sample, with no need to switch over to
standard endoscopic white-light illumination. It is thus possible
to work continuously during the procedure in fluorescence mode, in
which both the tumor to be treated and the instrument used for the
purpose, or its working elements, are clearly and unequivocally
recognizable. This thus creates the possibility of performing both
photodynamic diagnosis (PDD) and photodynamic therapy (PDT) under
consistent light conditions for the surgeon, i.e. with no switching
between white light and fluorescence mode.
In the case of the endoscopic instrument suite, the light source is
selected in such a way that the fluorescing substance on the
endoscopic instrument can be excited thereby.
Provision can be made for both the fluorescing substance on the
endoscopic instrument and the fluorescing substance in the tissue
to be excitable by one and the same light source and for each to
exhibit fluorescence of the same color; provision can also be made
for operating it with different wavelengths, and accordingly
achieving different fluorescence phenomena. The fluorescing
substance can be applied directly onto the instrument or can be
incorporated into it. It is, of course, always applied at a point
that is located in the observation region of an endoscope.
In a further embodiment of the invention, the marking is configured
as a marking element applied on the instrument.
The advantage of this feature is that the endoscopic instrument is
manufactured in the usual manner and then, if that instrument is
intended for fluorescence mode, the marking element with the
desired fluorescing substance can be applied.
In a further embodiment of the invention, the marking element is
applied removably.
The advantage of this feature is that the marking element can be
removed, for example for cleaning purposes or if the endoscopic
instrument is also to be used in nonfluorescing mode. This also
creates the possibility of applying correspondingly selected or
suitable marking elements to the endoscopic instrument for
different kinds of operations, or if different tissues are to have
different photosensitizers added to them.
In a further embodiment of the invention, the at least one distal
working element is equipped with a marking.
The considerable advantage of this feature is that by providing the
marking on the working element, the surgeon can detect with
particular precision the point at which the working element is
currently located, for example in order to begin and perform a
surgical procedure precisely.
In a further embodiment in which the working elements are
configured as two mouth parts, provision is made for them each to
be equipped with a marking.
The considerable advantage of this feature for the surgeon is that
he or she can bring, for example, the piece of tissue that is to be
detached precisely between the two spread mouth parts, i.e. can
accurately establish the position of the spread mouth parts
relative to the piece of tissue (also marked) that is to be
detached, and can then detach the tissue at a precisely determined
and appropriate point.
In a further embodiment of the invention, both the working element
and the proximal end section of the shaft are each equipped with a
marking.
This feature offers the advantage for the surgeon not only that he
or she can determine the position of the shaft relative to the
working elements, e.g. mouth parts, but also that this embodiment
can be utilized in particularly favorable fashion for "instrument
tracking." In instrument tracking, the endoscopic imaging system
(endoscope, camera) or the endoscopic image always tracks the
manipulating instrument. It is known from DE 195 29 950 C1 to
perform instrument tracking on the basis of large-area color
markings on instruments. In the body itself, however, all possible
colors of the visible region can occur, and it is therefore
impossible for a color datum acquired by the endoscope to be
assigned unequivocally to the instrument.
At present, an assisting surgeon guides the camera with the
proximally-mounted camera. The disadvantage associated with this is
that in long operations, manual tracking of the endoscope is no
longer performed with the necessary accuracy because the assistant
exhibits symptoms of fatigue, so that for brief periods the surgeon
is temporarily unable to see the surgical field. The endoscope may
move back and forth due to fatigue symptoms, so that image quality
is decreased by blurring. In this configuration, "solo surgery"
cannot be performed with the instrument suite. The provision of
multiple markings, or of markings that extend over a larger surface
region, now creates the possibility of accomplishing automatic
tracking by way of the fluorescent markings, since the particular
three-dimensional position can be exactly determined by the
equipment. If the position of the instrument having the markings is
then changed by the surgeon, the image sensing system can detect
this change in position and the observation system, for example the
endoscope, can be correspondingly shifted, i.e. "tracking" can be
performed. For example, external 3-D sensors which continuously
sense the position of the instrument can be employed so that via an
endoscope control device, the working area of the instrument is
always automatically made to coincide with the endoscope image.
In a further embodiment of the invention, the marking element is
configured as a tubular bushing that can be slid onto a tubular
shaft.
The advantage of this feature is that the marking element can
easily be slid onto the shaft. If this tubular bushing already has
a specific geometric extent, multiple definition points (for
example its beginning and its end) can already be utilized for
spatial positioning with respect to a fixed reference point.
In a further embodiment of the invention, the marking element has a
coating made of transparent glass, or a transparent plastic
coating, that covers the fluorescing substance.
The advantage of this feature is that the actual fluorescing
substance is hermetically isolated from the surgical field, but
nevertheless can be excited to fluoresce through the transparent
coating. As a result, it is then also possible to use fluorescing
substances that are not intended to come into contact with bodily
fluids, either because their fluorescence properties are thereby
changed or because those substances can be damaging to the tissue.
The selection of fluorescing substances usable in the medical field
is also substantially broadened thereby.
In a further embodiment of the invention, the marking element is
configured such that it can be inserted into the body on which the
endoscopic procedure is being performed, and can be anchored
there.
The advantage of this feature is that, for example in an initial
diagnostic step, a marking can be left behind or anchored so that
the location can be immediately recognized again in a subsequent
surgical procedure. In a surgical procedure that is possibly
performed by a surgical team other than the one performing the
diagnostic step, fluorescent excitation can be used for immediate
detection of the specially shaped marking and consequently also of
the tissue, marked with that marking, that is to be treated.
In a further embodiment of the invention, the fluorescing substance
is selected from the group comprising fluorescein, Acridine Orange,
the tetracyclines, eosin, cadmium sulfide, aminolevulinic acid,
aminolevulinic acid hydrochlorides, porphyrins, rhodamine B,
rhodamine G, auramine, auramine Carbol Fuchsin, and Nile Blue
sulfate.
These are common fluorescing substances or "fluorochromes."
In a further embodiment of the invention, the fluorescing substance
is selected so that it can be excited to fluoresce in the
wavelength range from 200 to 900 nm.
This wavelength range, which extends on either side beyond the
visible light wavelength range from 400 nm to 750 nm, offers a wide
range of applications. For example, excitation can occur in the
invisible UV range, thus achieving fluorescence in the visible
range. This feature has the advantage, for example, that the
excitation light is not perceptible and not disturbing to the
surgeon, who perceives only the fluorescence in the visible
range.
This also creates the further possibility of performing excitation,
for example, in the invisible UV range and achieving fluorescence
in the (also invisible) infrared range. This will be advantageous
if, for example, automatically monitored actions are taking place,
for example instrument tracking, which can take place without
influencing the surgeon's eye.
In this kind of embodiment of the invention the fluorescing
substance is selected, for example, so that it can be excited to
fluoresce in the wavelength range from 320 to 380 nm, i.e. by
invisible UV light, and fluorescence can then occur in the visible
range.
In a further embodiment of the invention, multiple markings with
differently excitable fluorescing substances are provided.
The considerable advantage of this feature is that an instrument of
this kind can be used flexibly for different diagnostic or surgical
procedures or in conjunction with different tumor-specific
photosensitizers, since because of the presence of the differently
excitable fluorescing substances, at least one substance that is
excitable for the specific purpose is then always present.
This capability can also advantageously be used in "instrument
tracking". For example, one or more markings that can be excited
outside the visible range and that optionally fluoresce outside the
visible range can be utilized for tracking, and a further marking
can be used as a marking visible to the surgeon.
In a further embodiment of the invention, multiple markings, which
contain different concentrations of fluorescing substances, are
present.
The advantage of this feature is that depending on local conditions
and the fluorescence intensity of the tumor, it is possible to work
in correspondingly compensated fashion, i.e. at high or low
intensity.
Marking in this fashion with differently excitable fluorescing
substances also makes it possible, when setting up an endoscopic
instrument suite with, for example, an endoscope and a video
camera, to establish an optimum irradiation intensity by way of the
excitation light source at the beginning of the operation.
In a further embodiment of the invention, the marking has a
fluorescing substance corresponding to that of a marking element
inserted into the body.
This feature, in combination with the previously mentioned feature
of the marking element inserted into the body, has the advantage
that it is possible to work with one and the same excitation
system, so that both marking elements already inserted into the
body, and the endoscopic instrument equipped with the corresponding
marking, are clearly recognizable by the surgeon and, for example,
the inserted element can also easily be grasped and removed again
with the medical instrument.
In the case of the endoscopic instrument suite, which has in
addition to the endoscopic instrument a light-supplying apparatus
and an endoscopic observation instrument, in particular an
endoscope, that is connected to an light source, it is furthermore
advantageous that at least one endoscopic manipulation instrument,
in particular a trocar, is provided, through which the observation
instrument can be introduced into the body, at least one marking
with a fluorescing substance corresponding to the endoscopic
instrument being provided on the inner side of the manipulation
instrument.
The considerable advantage of this feature is that the
functionality of a PDD or PDT system can be tested in vivo using an
intracorporeal reference. When the instrument, coated with the
fluorescing substance, is slid into the trocar, the functionality
of the system can be checked by way of the fluorescing substance
distributed over the inner side surface. It is in fact additionally
possible to adjust various parameters--for example sufficient power
density of the excitation light or the spectral composition of the
excitation light--optimally for the particular application. In
addition, an optimum color adjustment for a camera sensing the
endoscopic image can be performed.
In the case of an endoscopic instrument suite of this kind, it is
further advantageous that the observation instrument is an
endoscope that is equipped with an endoscopic camera.
The advantage of this feature is that the surgeon need not work
directly at the endoscope, but that instead the image is acquired
via an endoscopic camera, so that is it thus possible to store that
image information, for example in order to identify changes upon
subsequent examinations or to convey the image information to an
image processing system for better processing. For example,
information that was obtained in a diagnostic procedure can be
compared, at the beginning of an operation, to the data acquired at
that time and, for example, progression of the tumor or perhaps
even shrinkage as a result of other chemical treatments can be
detected. This also makes it possible to sense the decrease in
fluorescence during a PDT treatment (PDT dosimetry), for example by
way of marked elements left in the body.
In a further embodiment of the invention, there is provided
downstream from the endoscopic camera an image processing system
that continuously detects the fluorescing markings in the
endoscopic image.
The advantage of this feature is that because of the image
processing system, it is possible by way of suitable filters to
suppress interfering or undesired fluorescence phenomena or to
amplify weak signals. so that the surgeon is provided with an
optimal image of both the tissue and the marked instrument.
In a further embodiment of the invention, the light source emits
pulsed light at least in the spectral excitation range of the
fluorescing substance, the pulse frequency corresponding to the
video image frequency or video frame frequency of the endoscopic
camera.
The advantage of this feature is that precise instrument tracking
can be performed with this pulsed technique and that even very
small changes in position, which cannot be perceived by the human
eye, can be sensed. The PAL standard is 25 and 50 Hz, and the NTSE
standard 30 and 60 Hz. The pulsed technique allows instrument
tracking without thereby influencing or disturbing the human eye,
since at the image frequencies usual in video technology, the human
eye is too slow-reacting to perceive differences.
In a further embodiment of the instrument suite, provision is made
for the observation instrument to have, at the distal end, a
transparent element having a fluorescing substance.
The considerable advantage of this embodiment is that reflected
light received by the observation instrument, which lies in the
nonvisible region, can be converted into a visible fluorescence
phenomenon by the fluorescing substance that is excited in that
region.
It is understood that the features mentioned above and those yet to
be explained below can be used not only in the respective
combinations indicated, but also in other combinations or in
isolation, without leaving the context of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained and described in more detail below
with reference to a selected exemplary embodiment.
In the drawings:
FIG. 1 shows a highly schematized view of an endoscopic instrument
suite during an endoscopic procedure; and
FIG. 2 shows a greatly enlarged partial perspective view of the
distal end section of the endoscopic instrument that is used in
this operation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1, an endoscopic instrument suite is labeled in its
entirety with the reference number 10.
Endoscopic instrument suite 10 has an endoscopic instrument 12 and
an endoscope 14.
Endoscopic instrument 12 is a grasping forceps that has an
elongated tubular shaft 16. At the proximal end, shaft 16 is
equipped with a handle that comprises two scissor-like handle
elements interconnected via a hinge. A working element 20, in the
form of two mouth parts 22 and 24, is arranged at the distal
end.
Mouth parts 22 and 24 are connected to the handle via an actuating
element 19, so that pivoting of the movable handle element causes a
linear movement of actuating element 19 along shaft 16, and mouth
parts 22 and 24 are spread or closed depending on the direction of
movement.
As is evident from the enlarged partial presentation of FIG. 2,
each mouth part 22 and 24 is equipped with a marking 26 and 28. In
addition, a further marking 30 is provided in the region of the
distal end of shaft 16.
Markings 26 and 28 of mouth parts 22 and 24 comprise separately
attachable marking elements 32 and 34.
Marking elements 32 and 34 are of semicircular configuration, and
can be clipped in immovably adhering fashion from the outside onto
mouth parts 22 and 24.
Each marking element 32 and 34 comprises a transparent plastic
double film between which a fluorescing substance is embedded. A
"fluorescing substance" is understood to be a substance that
exhibits fluorescence following excitation with light of a specific
wavelength range. The wavelength range of the excitation light lies
in the range from 200 nm to 900 nm, i.e. encompasses the range of
visible light (approximately 400 nm to 750 nm) as well as the
invisible UV and IR regions.
Marking 30 comprises a tubular bushing 36 that is slid onto the
outer side of shaft 16 and has a respective marking ring 38 and 40
at its opposite ends.
Marking rings 38 and 40 also contain a fluorescing substance, which
can be the same as the fluorescing substance of marking elements 32
and 34 or can also be a different fluorescing substance, for
example a substance that can be excited in the UV range and
exhibits fluorescence in the IR range.
Endoscope 14 has an endoscope shaft 46 that is introduced, through
a manipulation instrument 42 in the form of a trocar 44, into a
body cavity through an abdominal wall 60 of a human body.
Endoscope shaft 46 is joined proximally, via a lateral extension,
to a light source 48. Light source 48 can radiate ultraviolet (UV),
visible, and/or infrared (IR) light; very specific wavelength
ranges, and multiple defined wavelength ranges, can also be
radiated. Endoscope shaft 46 contains light guides in the form of a
glass-fiber bundle which delivers at the distal end of endoscope
shaft 46 the light proceeding from light source 48, as indicated by
arrows 49.
Also received in endoscope 14 is an optical system 50 that
comprises a rod lens system, arranged in endoscope shaft 46, which
ends at the proximal end in an eyepiece equipped with an eyepiece
cup 52. Fluorescent light incident at the distal end of endoscope
shaft 46, as indicated by an arrow 51, can thus be guided through
the optical system to the distal end of endoscope 14.
If, for example, a tissue sample is to be taken from a tissue 62
present in the body, both endoscopic instrument 12 and endoscope 14
are introduced, in a manner known in the minimally invasive
surgical technique, through small body openings, e.g. through
abdominal wall 16. These body openings are usually created by way
of trocars or their trocar mandrels. Following insertion of both
endoscopic instrument 12 and endoscope 14, the surgeon can place
his or her eye against eyepiece shell 52 and observe the regions
visible in the abdominal cavity beneath abdominal wall 16. In the
above-described technique of photodynamic diagnosis (PDD), a
precursor of a photosensitizer, e.g. aminolevulinic acid (ALA), has
previously been administered to the patient. If a tumor 64 is
present in the region of tissue 62 being examined, the ALA
photosensitizer precursor accumulates in it, and the accumulated
fluorescing substance can be excited by a corresponding excitation
light, in this case in the blue (380 nm to 430 nm), to fluoresce
via a specific conversion process, this fluorescence occurring in
the red (635 nm). If the tissue 62 shows autofluorescence one can
excite to autofluorescence in the respective excitation range of
the tissue, for example in the range from 400 nm to 500 nm. As
described earlier, light source 48 is configured such that it emits
either white light or a special light in the ALA excitation range,
i.e. blue light from 380 nm to 430 nm. If a medical instrument were
made of medical steel, as is usual for endoscopic instruments 12 in
the form of a grasping forceps for removing a tissue sample, this
forceps would be very difficult to detect. Because endoscopic
instrument 12 is now equipped with markings 26, 28, and 30, these
markings are also excited to fluoresce. In the simplest case, the
marking is selected so that it contains a fluorescing substance
that can also be excited with blue light and exhibits fluorescent
phenomena in red light. The surgeon can thus detect, via optical
system 50 of endoscope 14, both fluorescing tissue 62 and also
fluorescing markings 26, 28 and optionally also 30 of endoscopic
instrument 12, and thus can remove the tissue sample precisely
using endoscopic instrument 12. In the case of a surgical
procedure, endoscopic instrument 12 can be configured as a cutting
forceps that detaches, for example, a tissue area affected by a
tumor 64.
In FIG. 1, the dot-dash line indicates an endoscopic camera 54 that
is placed onto eyepiece shell 52 of endoscope 14. Endoscopic camera
54 is connected to an image processing system 56 that generates a
video image 58 on a monitor.
In this instance the surgeon can observe the surgical region by way
of the monitor. It is evident from video image 58 that at the
aforementioned excitation frequency at which the precursor ALA
exhibits fluorescence by conversion into photoporphyrin, this
occurs to a greater extent in the region of a tumor 64 on tissue
62. Also visible on video image 58 is the distal end region of
endoscopic instrument 12, or at least the markings of mouth parts
22 and 24. It is thus possible to remove in very specific fashion,
for example, a tissue sample in the region of tumor 64.
The interposition of an image processing system 56 makes it
possible to perform instrument tracking, i.e. endoscope 14 can be
displaced via an actuating drive (not shown here in further
detail). For this purpose, light source 48 radiates pulsing light
that specifically excites marking 38, and also optionally markings
26 and 28 on mouth parts 22 and 24, to fluoresce. With these three
location parameters, the three-dimensional position of endoscopic
instrument 12 relative to endoscope 14 can be sensed via external
3-D sensors, and can be coupled to the actuating drive for the
endoscope. If the position of endoscopic instrument 12 is then
changed, this is sensed by image processing system 56 which sends a
corresponding signal to the actuating drive, which then brings
endoscope 14 into a position such its optical sensing region at the
distal end once again senses the distal end of endoscopic
instrument 12. Thus as the surgeon, for example, approaches tumor
64 of tissue 62 with endoscopic instrument 12, the control system
is such that mouth parts 22 and 24, and marking 38 on the distal
end section of shaft 38, are always within the optical field of
view of optical system 50.
Present on the inner side of trocar sleeve 44 are markings with
numerous fluorescing substances, for example including the
fluorescing substances that are present on mouth parts 22 and 24
and on marking 38; ALA is optionally also present as a reference
substance. When the distal end of endoscope shaft 46 is slid in
through trocar 14, it is thereby possible to put light source 48
and image processing system 56 into service even before the distal
end has penetrated into the body cavity, in order to ascertain
whether the system is working; image compensation can also be
performed at the same time. If the pulsing is performed, for
example, at the video frequency of the camera system (50 Hz for
PAL, 60 Hz for NTSC), the marked point can then be determined very
easily by referencing the color values of successive frames.
Because of the relatively high frequency, a human observer cannot
resolve the color differences in time, and therefore does not
perceive the disruptive difference. The same applies in the case of
an excitation in the visible and a specific fluorescence in the IR
region.
Using sensing by way of at least two spatially associated image
sensors, instruments marked with fluorescent substances make
possible position detection, i.e. localization of the spatial
instrument coordinates or direction. Because these points are
marked with fluorescing substances that radiate differently in
terms of wavelength and/or are marked differently in terms of
surface extent, no ambiguity in allocation occurs in the image
sensing chips. This also creates the possibility for image
processing system 56 to detect not only where endoscopic instrument
12 is located, but also whether the correct instrument is being
used.
* * * * *